Star polyps, green star polyps, brown star polyps, whatever you call them, are one group of corals that we don’t appreciate nearly enough. Nine out of ten reefers couldn’t tell you the scientific name of this important aquarium coral, or tell you how many different species there are.
Reefers might take green star polyps for granted, but that hasn’t stopped scientist from describing a new species in the genus Briareum. Briareum cylindricum is a new species of this encrusting form of ‘polyp’ coral, described in a recent paper that brings the total number of Indo-Pacific species in the genus to four.
The cylinder part of Briareum cylindricum refers not to the appearance of the coral, but to the shape of the sclerites in its tissue, whose microscopic shape and characteristics are often used to describe octocoral species. You may not be able to see the
sclerites of B. cylindricum, but the species is still readily distinguished by having a pattern of small bumps and tubercules visible on the encrusting mat between the polyps.
The description of ‘cylindrical’ star polyps doesn’t show the living polyps of Briareum cylindricum, but we immediately recognized the look of the small dried mat that is pictured as the holotype for the species. Countless of you reading this right now have experience fragging green star polyps and we are certain that this species has been imported into the aquarium hobby already.
Now that we know that this particular green star polyp is a new species, we’ll be keeping an eye out for it and see if the tentacles betray its identity from other species of Briareum. The newest species of encrusting star polyps Briareum cylindricum is described from the Indo-Pacific by Smimi-Namin & van Ofwegen in the January 2016 volume of ZooKeys.